2015-015 - Addendum to the Final Environmental Impact Statement /Environmental Impact Report No. 89-01

Home Browse Search

ENVIRONMENTAL IMPACT REPORTADDENDUM Bristol Street Widening Phase IIIA— Civic Center Drive to Washington Avenue TABLE 2 PROJECT RELATED CONSTRUCTION EMISSIONS Demolition VOC NOx CO S02 PMI0 PM2.5 70 44 <1 12 3 Trenching 5 41 19 <1 2 2 Grading 8 60 34 <1 6 4 Paving 3 16 11 <1 2 1 Maximum 9 70 44 <1 12 4 SCAQMD Threshold 75 100 550 150 150 55 Exceeds Threshold? No No No No No No Source: Air Quality Assessment Report (URS 2013a), Notes: VOC = volatile organic compounds; NOx = nitrogen oxides; CO = carbon monoxide; S02 = sulfur dioxide; PMlo = particulate matter less than less than or equal to 10 microns in diameter; PM25 = particulate matter less than less than or equal to 2.5 microns In diameter An assessment of regional emissions associated with the operations phase of the proposed Project was also conducted which compared emissions with and without the proposed Project. Air pollutant emissions generated by roadway vehicles are quantified based on emissions rates that vary based on vehicle speed. Because the proposed Project would increase the roadway capacity along Bristol Street, traffic congestion would be alleviated and average vehicle speeds would increase along improved roadway segments. Table 3 shows the emissions that would occur with and without the proposed Project based on the average vehicle speeds. As shown in Table 3, air pollutant emissions would be less under the With- Project Alternative as opposed to the No Project Alternative due to the lower emission rates associated with higher average vehicle speeds. The SCAQMD has established significance thresholds to determine whether the operations phase of projects would result in significant impacts to regional air quality. The proposed Project would result in air pollutant emissions which are below these significance thresholds and would result in a beneficial impact on air pollutant emissions due to improvements in operational phase efficiencies along Project roadway segments for the 2015 Project opening year. Emissions occurring during the 2035 design year were also quantified based on the LOS, average vehicle speed and emission rates that would occur with and without the proposed Project. As shown in Table 4, air pollutant emissions occurring under the With- Project Alternative would be less than under the No Project Alternative due to lower emission rates associated with higher average speeds. Consequently, the Proposed Project for the 2035 Project design year would likewise result in emissions which are below the SCAQMD's significance thresholds and would result in a beneficial impact relative to greenhouse gas (GHG) emissions due to improvements in operational phase efficiencies along Project roadway segments. Mitigation Measures No additional new mitigation measures are required. TABLE 3 YEAR 2015 WITH AND WITHOUT PROJECT AIR POLLUTANT EMISSIONS ROADWAY - AVERAGE ,INTERSECTION VEHICLE CO ROG NOX SOz PM10 I'l -SPEED Year 2015 No Protect Civic Center Drive and Washington Avenue Bristol Street 13 69 12 ANA 305 -011 (PER 02) CITY OF SANTA ANA (01/19/2015) YU PAGE 31